Method of making heels



June 18, 1929.

c. ROBERTS 1,717,583

METHOD OF MAKING HEELS Filed Oct. l5, 1925 714m@ WMV Patented June 18, 1929.

UNITED STATES PATENT OFFICE.

CLIFFORD ROBERTS, OF WINCHESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO UNITED SHOE MACHINERY CORPORATION, OF PATERSON. NEW JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF MAKING HEELS.

Application led October 15, 1926. Serial No. 141,770.

The present invention relates to a method of making heels for boots and shoes, and.

more particularly to improvements in the manufacture of heels of this character comprising a body portion of'rubber compound having embedded therein an attaching core of wood or similar or equivalent nail-retaining or filler material.

The advantages of rubber heels employing embedded cores capable of penetration by the attaching nails are self-evident. The use of this type of core provides'a nailing area extending throughout the 'major portion of the heel inside of the margin, insures a firm adherence of the heel to the boot or shoe, and effects a saving in rubber compound without substantial interference with the elasticity andwearing qualities of the heel. In producing heel members of rubber compound, or similar vulcanizable material, having embedded attaching cores, diiculty has heretofore been experienced in obtaining a heel properly adapted for the maintenance of a tight edge. I have discovered that the defect l`heretofore existing in these heels is due primarily toa shrinkage of the rubber compound after the formation and vulcani- Zation of the heel, with a resulting distortion of the heel shape due to the inclusion therein of the substantially non-shrinkable core, this distortion being most pronounced adjacent the marginal portion of the heel. In some instances and with certain types ofl core, the shrinkage of the rubber compound 'v upon cooling may additionally produce a distortion of the core itself, tending to further distort the resulting heel shape.

I am enabled to produce rubber heels free from distortion and having embedded cores of the above-describedcharacter by initially raising or elevating that portion of the attaching face adjacent the margin in a manner to compensate for the increased shrinkage which normally occurs in this portion of the heel as contrasted with the shrinkage which occurs in the central portion of the heel underlying the core. The result of this elevation of the attaching face at its marginal portion bv a predetermined amount is to counteract the distortion, due to shrinkage throughout this portion of the heel, and produce a finished heel of the desired shape which permits the maintenance of a tight edge when secured to the Hat heel seat of a boot or shoe. In the usual practice of the invention, a ply-wood core somewhat smaller than the area of the heel and of a depth approximating not lnore than half the depth ofthe heel is embedded in the heel body at the attaching face and completely surrounded at its marginal edges by rubber compound. That portion of the heel body surrounding the core is slightly elevated above the normal surface of the attaching face, 'as determined by the face of the core, and in suiiicient amount to compensate for shrinkage and resultant distortion which occurs in the marginal portion of the heel body surrounding the corepand which otherwise tends to cause an inclination of the mar ginal portion of the attaching face extending downwardly from the juncture of the edge of the core and heel body to the outer marginal edges of the heel. Thiselevation of the attaching face, which preferably takes the form of an upward inclination of the attaching face extendin from the edge of the core to the margin o the heel body, isin no sense of the word the equivalent of a sealing rand on the finished heel, and in fact does not appear in the finished form of heel. In actual practice the heel mold is designed to initially impart this relatively slight elevation to the attaching surface, and upon cooling of the heel body after vulcanization the resultant shrinkage and distortion restores the heel to the desired form.

In the drawings illustrating the preferred form of the invention,

Fig. 1 represents a section of a cavity designed to initially impart the desired marginal elevation to the heel body;

Fi 2 represents a section of the resulting heel ody after removal :from the mold and cooling; and

Fig. 3 represents a section of a heel showing in a somewhat exaggerated manner the form which the finished heel assumes if no provision is made for non-uniform distortion.

According to the illustrated embodiment of the invention, a heel mold is provided with the usual mold cavity 10, upon the bottom of which is located a wooden heel-shaped core 12. The heel body of rubber compound 14 surrounds the core within the mold and initially assumes the shape of the mold cavity. As indicated, the breast edge 16 of the heel body at the attaching face is offset from the plane of the attaching face, as determined by the face of the core, and slopes downwardly from this point to the juncture of the heel body with the adjacent edge of the core. The elevation of the edge above the attaching face may vary throughout the margin of the core, may be of uniform height, or may be confined to the breast edge, depending upon the shape of the heel and the location of the core, that is to say, the width of the margin separating the edge of the core from the upper edge of the heel.

What is claimed is:

1. A method of making heels for boots and shoes having a body portion ofrubber compound with a atcore of non-shrinkable liller material embedded therein at the attaching face, which consists in initially molding and vulcanizing the heel shape with the outer edge thereof at the attaching face elevated above i the flat face of the core a sufficient amount to insure against projection of the core above the outer edge upon cooling and shrinkage of the heel shape.

2. A method of making heels for boots and shoes having a body portion of rubber compound with a fiat core of non-shrinkable iiller material embedded therein at the attaching face, which consists in initially molding and vulcanizing the heel shape with the marginal portion of the heel shape at the at` taching face surrounding the core inclined upwardly in a definite and predetermined manner from the junction with the core to the outer edge of the heel shape to insure against projection of the corel above the attaching face after completion of the heel, and thereafter cooling and permitting the heels to shrink to the desired shape.

In testimony whereof I have signed my name to this specification. p

CLIFFORD` ROBERTS. 

